The Internet provides users with convenient and ubiquitous access to digital content. Because of the potential of the Internet as a powerful distribution channel, many consumer electronics (CE) products strive to directly access the Internet or to interoperate with the PC platform—the predominant portal to the Internet. The CE products include, but are not limited to, digital set top boxes, digital TVs, game consoles, PCs and, increasingly, hand-held devices such as PDAs, mobile phones, and mobile storage and rendering devices, such as Apple's iPod. The use of the Internet as a distribution medium for copyrighted content creates the compelling challenge to secure the interests of the content provider. In particular it is required to warrant the copyrights and business models of the content providers. Increasingly, CE platforms are operated using a processor loaded with suitable software. Such software may include the main part of functionality for rendering (playback) of digital content, such as audio and/or video. Control of the playback software is one way to enforce the interests of the content owner including the terms and conditions under which the content may be used. Where traditionally many CE platforms (with the exception of a PC and PDA) used to be closed, nowadays more and more platforms at least partially are open. In particular for the PC platform, some users may be assumed to have complete control over the hardware and software that provides access to the content and a large amount of time and resources to attack and bypass any content protection mechanisms. As a consequence, content providers must deliver content to legitimate users across a hostile network to a community where not all users or devices can be trusted.
One way to protect copyrighted data is to encrypt it or to encode it in a proprietary format such that the content can only be used with a proprietary program. The proprietary program contains code to enforce a digital rights management policy. If a user is allowed to access the data, then he/she may be allowed access to a key via the proprietary program for decrypting or decoding it.